For people who were actually interested in using Ada, the early poor tooling was the main impediment. However, I think the bigger issue is that it was moving directly against the cultural headwinds at the time.

The immediate response I heard anytime Ada was mentioned was that it was a designed-by-committee language[1] that couldn't even be fully implemented due to a theoretically impossible specification[2]. It was made by a bunch of bureaucratic stiffs and was all about constraining the developer with stupid rules and bogging them down with verbosity. It was contrary to the freewheeling nature of the PC developer culture that sprung up in the 70's and continued through the 80's, and then evolved into the dot-com developers of the 90's and 00's.

It took decades of wandering through the deserts of "Real Developers don't write buffer overflows" on one end, and "Performance doesn't matter, and a sufficiently smart compiler will provide it anyway" on the other to get to the point where mainstream developers wanted a language that combined the safety of high-level languages with the control of low-level languages.

[1] This is false, it was selected in a contest with each entry developed independently.

[2] True but overrated